1. Field of the Invention
The present invention relates to a stream generating apparatus for generating a TS (Transport Stream) from the video signal in accordance with, for example, MPEG2 (Moving Picture Experts Group 2) and a method of supplying a frame sync signal used for the stream generating apparatus.
2. Description of the Related Art
In digital broadcasting, the studio equipment for the signal processing such as encoding the video signal in accordance with MPEG2 and TS multiplexing are essential. Also, digital broadcasting requires more delicate and accurate processing than analog broadcasting. To meet this requirement, the BB (Black Burst) reference sync signal for the video signal is introduced from an external source to generate a frame sync signal, and each piece of studio equipment is controlled with this frame sync signal.
In the case where the BB reference sync signal is at fault, however, the intervals of the frame sync signal become irregular, whereby data drop-off or duplication of the video signal, frame drop-off, abnormal encoding rate, abnormal output rate, buffer breakdown, or the like is caused. These situations result in an abnormal TS.
A conventional method, which uses a flywheel counter to independently generate a local frame sync signal, is used in the case where the sync information failed to be acquired in the studio equipment (for example, Jpn. Pat. Appln. KOKAI Publication No. 2000-183863).
Even the method using the flywheel counter, however, requires the adjustment of the flywheel counter, and this adjustment incurs troublesome manual work on the part of the operator.